Engine



oct'. 27,1925. 1,559,107

. y L. S. KEILHOLTZ ENGINE original Filed. sept. 26. 1923 Patented Oct. 27, 1925.

.UNITED STATES y PATENT OFFICE.

LESTER s. xEILEtoL'rz, or .nmr'rcyngV onto, AssIGNo-n'ro manco-LIGHT COMPANY, or

' DAYTON, omo, A coEoRA'rroN or DELAWARE v ENGINE. s

Application illed September-26, 1928, Serial No. 684,945. Renewed July 23, 1925.

To all 'whom t may concern.' e Be it known that I, LESTER S. KEmHorfrz, v-a citizen of the United States of America,

and useful Improvements in Engines, of which the following is a full, clean-and ex- 'act description.

vThis invention relates to engines and includes among its objects the-elimination of noise and compensation for wear in the mechanism for operating .the valves of an engine.

Further objects and advantages of the present invention will be apparent fr om the following description, reference belng had to the accompanying drawings, whereinv a preferred form of embodlment of the present linvention is clearly shown.

`In the drawings: p

Fig l is a fragmentary view of` an internal-combustion engine partly in section;

Fig. 2 is a sectional View on -une 2-2 of Fig. 1; l

Fig. 3 is an end view ofa friction member cooperating with the valve 'operating mechanism; and

Fig. 4 is an end view showing a supportv for the friction members shown in Fig. 3. Referring to the drawings, 20 designates the crank case of an internal-combustion,v

engine which supports bearings 21 and 22 which support for rotationa crank shaft 23 provided with a crank 24 cooperatingwith a connecting rod 25 connected with a piston 26 which reciprocatesiin a cylinder 27.

The engine is provided with a plurality of poppet valves, one being-.shown at 30 in Fig. 1. Valve 30 is mounted to slide in thecylinder head 31 and is retained'on its seat by meansof a spring 32 bearing agalnsta washer 33 carrled by the stem of\the valve 30.,V

The valve operating mechanism includes a rocker arm 34 pivotally mounted at 35 upon the cylinder'head 31 and actuated by push rod 36 s'lidably mounted in a ort 37 of the crank case 20. The lower en of the push rod is adapted to be engaged bycam 38 provided on cam shaft 39 having Jour- 'nals 40 and 41 mounted to rotate in bearings 42 and 43, respectively, provided by the crank case 20. The crank shaft 23 carries a spiral gear 44 meshing with a spiral -gear 45 on 4the cam shaft 39. For each of -shaft 39. This device includes a non-metallic or ber washery 50 located between the end surface of the bearing 42 and the shoulder 51 provided on the cam shaft 39, and also a non-metallic friction member 52 made of material such as cork which abuts the flat end surface 'of the journal ortion 41 of cam shaft 39 and is held in yie ding engagement ltherewith by means of a s ring 53 bearing at one end against a member 54 which carries the friction material 52, and at the other end lagainst a cap 60 secured by screws 55 to. the crank case 20. As shown in Fig. 2 the cap 60 is provided with a recess 56 for receiving the spring 53 and with a recess 57 continuing from the recess 56. Recess 57 is bounded by the ilat surfaces 58 cooperating with flat surfaces 59 on the retaining memvber 60 in order to prevent' rotation of the 51 and the bearing 42 thereby taking up v any end play in the shaft 39. Due to friction between the end surface of the en# larged journal 41 ofthe shaft 39 and the friction member 52,A there is a tendency for the working faces of the gear teeth of gear 4 5 to remain in engagement with the Working 'faces of the gear teeth of `gear 44 'althouglthere may be someclearance between these gears. 'This frictional device tends to prevent intermittent separation of the work-y overcomingthe tendency ofthe springs 32' 105 of the valve mechanism to produce rota-pv tion of the cam shaft 39 in a sense opposite that produced by the driving of the gear 45 by the gear 44.

It has been found that the present invention materially reduces the lash of the gear teeth of gears 44-and 45 ,thereby miniand 45` to be reversed.

While the preferred form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as followsz 1. In valve operating mechanism for internal combustion engines and in 'combination with the crank case of the engine, a Valve operatin shaft the ends of which are supported in earings in oppositely disposed walls of the crank case; a thrust collarfadjacent one end of said shaft and cooperating with one of said bearings to pre-' ,vent longitudinal movement of the shaft;

a hollow cap removably secured to the exterior of said crank case and overlying the other end of said shaft; avfriction member engaging said last `mentioned end of said shaft; and a spring located within said hollow cap and acting against said friction member to press it against the last mentioned end of said shaft.

2. In valve operating mechanism for internal combustion engines and in combination-with the crank case of the engine; a

valve operating shaft the ends of which are i said shaft; a friction member in contact with said enlarged end; means whereby rotary movement of said friction member is restrained by said cap; and a spring located within said hollow cap and acting to press said friction member against the enlarged end of said shaft.

3. Valve operating mechanism for internal combustion engines comprising, in combination, a crank shaft having a ear, a valve cam shaft having a gear mes ing with the gear of the crank shaft, and a stationary friction member bearing against an end of the valve cam shaft, thereby maintaining the working faces of the gears in engagement.

l In, testimony whereof I hereto aiiiX my signature. t

' LESTER s.' KEILHOLTZ. 

